What is Mastodon? Why is Mastodon? How is Mastodon?
20 min read

What is Mastodon? Why is Mastodon? How is Mastodon?

It isn't exactly a Twitter replacement, but IMO it's pretty cool. So I hope I can demystify it for you a bit.
The Mastodon mascot, a mastodon.
The mastodon. Y'know, from Mastodon?

Also where and when and who is Mastodon?

This post was last updated 11/22/2022 to provide better, more up-to-date guidance on picking a server.

The past few weeks on Twitter, things have gotten... very strange. Through all the chaos, you may have heard chatter about whether Mastodon could be a suitable replacement for Twitter.

In my opinion, the answer is "not exactly." Mastodon and Twitter are pretty different, technologically, operationally, and culturally, so if you're looking for a 1:1 replacement, Mastodon isn't that. But I do think Mastodon is pretty cool, and I hope that this sudden spike in attention for Mastodon gets lots of new people interested in how it might offer them an opportunity for a different kind of social media experience.

So the purpose of this post is to demystify Mastodon a bit, to help you decide whether it’s right for you, and if it is, to get you started in a way that helps you get the most of out. There’s kind of a lot to explain, but the good news is that most of it isn’t stuff you really need to know, it’s more that it’s stuff you might want to know. So feel free not to read the entirety of this very long write-up, and just skip to the sections that you’re curious about.

If what you're curious about is my credentials, the answer is I have none. I've been an infrequent Mastodon user for a few years, and a regular for about seven or eight months. I've been running my own Mastodon server for six months. Also in my professional life I've got about a decade of experience onboarding new, non-technical fundraisers into how to use fundraising ERP systems, so my instinct to "help get you up and running" is deeply ingrained at this point.

Table of Contents

What exactly is Mastodon?

Mastodon is a social network that has a lot of the same functionality as Twitter, but isn’t owned or operated by any one organization. Instead, it’s made up of lots of different servers (sometimes called “instances”), all talking to one another.

If you only take away three things from this post, let it be these three things:

  • Mastodon is made up of many servers that can all talk to one another. When you set up an account, you’re not signing up with a company called “Mastodon”, you’re signing up with a server, run by an admin. Anyone can make a server, which is both exciting and also kind of scary. The server you sign up for will give you access to Mastodon, but Mastodon is bigger than your server.
  • If you want to follow people on a particular server, you don’t need an account on that server! The servers are not separate universes. An account on your Mastodon server has the ability to follow, reply, and interact with accounts on all the other Mastodon servers (except the servers that your server admin has deliberately blocked).
  • You can move servers later!. If you're on a server and you later decide you'd prefer to be on a different server, you can move without losing your followers. However, it's a multi-step process and it your old posts will stay where they are, you can't currently take those with you.

I think when a lot of people first hear about Mastodon, these three things are the most frequent, immediate points of confusion, and the biggest barrier to entry. So before anything else, I wanted to make those things clear.

Cool, I get it, where do I sign up?

Wow, really? That was fast. Skip down to here.

Wait hold up, I still don’t get it.

Yeah, that’s understandable. Let’s get into it, shall we?

Why'd they have to go and make things so complicated?

A recurring motif in the discussion about Mastodon on other platforms has been that it’s too complicated. It's laden with incomprehensible jargon, and learning the ropes feels like “homework.”

Some Mastodon evangelists respond condescendingly to this confusion. “Actually it’s really simple”, etc. But I am here to tell you that they are wrong. If you are confused and daunted, then that is understandable. Mastodon is more complicated to use than Twitter, it just is. Both in terms of its basic structure, and in terms of the techy jargon it expects you to use (like “server” or “instance” or “federated”).

I think the jargon could definitely use some work, to make it more inviting for people who don’t see themselves as tech nerds. But as to the basic structural complexity, what I ask you to consider is this: What if it's actually a good thing that Mastodon is a little complicated and you need to spend a bit of time learning before you jump in?

Corporate social media platforms like Twitter and Facebook make everything so, so, easy. It’s easy to sign up, it’s easy to find what you’re looking for, and they make it nice and easy to stay engaged by algorithmically pushing just the right content and ads at you in just the right times and places. This ease of use is not for your benefit, it’s to hook you quickly and keep you hooked so they can sell your attention to advertisers.

Mastodon isn't built for profit, so it isn't built to do what those platforms do. It's almost like Mastodon is prompting you to use it with consideration and intentionality. It wants you to pause and to wonder “Wait, what exactly is it I'm signing up for? Who runs this and why? What are my options here? What do I even really want out of this?"

I think these are good things to be thinking about.

What’s all this about connected servers?

The idea of connecting servers this way is called “Federation,” and it’s actually kind of an old-school concept. The Internet is kind of built on the model of separate systems talking to one another. That's how email works, or the web. But most of us are not used to thinking about the Internet in that way, so it feels unfamiliar and strange.

Each Mastodon server is operated seperately, but they are connected, or “federated”, to form one big social network. People often call this network of interconnected servers the “fediverse.” [1]

So when you sign up for a Mastodon server, you’re not just signing up to follow and reply to the people on that server. That server is providing you with access to all the users on all the servers (except the ones your server has decided to block). Even though you’re using different servers, you can interact with one another just the way you’d be able to on unified services like Twitter or Facebook.

Think of it like email. You know how with email, you can email anyone you want? Like for example: if I have gmail, and you have an email from your university, we can still send emails to one another, no problem. Our email providers might offer different features, like spam filters, address book functionality, calendar integration, storage, etc. But that doesn’t mean we can’t interact.

Mastodon works kind of like that. Your server is your service provider. You sign up with them, and they provide you with access to the larger fediverse.

So if they’re all interacting, what’s the point of having separate servers? Wouldn’t it be simpler to have one single unified service, like twitter?

Yeah, that is simpler. That’s one of the reasons Facebook, Twitter, etc have been so popular—they’re easy and frictionless. This works great for those services—most of us barely have to think twice about the process of signing up, which has made it really easy to grow those services.

But Mastodon has different priorities, so it’s been built with different trade-offs in mind. One great thing about the federated model, despite its being more complicated, is that no one person or organization can make dumb decisions and ruin the whole system for everyone. No profit motive, no forcing ads or spyware on users, and no billionaires buying it all up and making it shitty.

It also means each server can set its own policies for acceptable content. For example, you could have strict policies against hate speech and harassment, or very specific/detailed guidelines for when to use content warnings (which are one of Mastodon’s best features).

Of course, It also means nazis can create their own server and run it however they want, and believe me they do. But the admin of your server can just block their whole server. Zap, gone, they don’t exist to you.

But if nobody’s in charge, who built it? Who adds new features? Wouldn’t that person be in charge?

That is a great question. Mastodon is a project created by Eugen Rochko. He heads up the development of new versions of the software, and he runs two of the largest Mastodon servers, mastodon.social and mastodon.online.

So it sounds like Eugen’s the boss, right? Well, yes and no. He does have a lot of influence, but he doesn’t have the ability to make unilateral decisions that directly affect how other servers run things.

For example, if Eugen turned totally evil (he won’t, but roll with me here), he could decide that he wanted Mastodon be a haven for hate speech, and put policies in place that encouraged that. But he can only enact those policies on his two servers. My server can still set its own policies. And if things get really bad with Eugen’s servers, we could block those servers and only “federate” with servers who were still cool.

Of course, those policies would suck for people on his servers, but they could leave and find new servers to use. This isn't too hard to do, because Mastodon has a handy migration feature that lets you move your account, and take your followers with you.

Or another example, and this is once again unlikely to happen: if Eugen gets some dumb ideas and adds a bunch of garbage features to the mastodon software, like ads or spyware or features I just hate, he can’t force them on me and my server. When he implements those features, he'll do it by putting out an update to the software. But I don’t have to apply that update on my server. I could just keep running whatever version of the software I’m already running, or revert to an even older version. Or I could take the source code (it’s open source!) and modify it to build my own version of Mastodon, with the features I want. There’s nothing Eugen could ever do to stop me from doing that.

It might sound a bit extreme to set up a whole alternate version of the software, but actually, there are already a number number of “forks” (that’s developer speak for alternative versions) of Mastodon out there, like glitch-soc and Hometown.[2] This isn’t because of an acrimonious split with Eugen, but rather because some eager developers had cool ideas for features they wanted to add, so they just went ahead and made their own versions with those added features. Some of the features from those forks have even ended up being incorporated “upstream” into the main version of Mastodon.

So I get that I have to sign up with a server, but how do I pick one? Does the server I pick matter?

This is one of the points where prospective users can get hung up. I get it. It's easy to see a list of servers, have no idea which one you should pick, and just give up.

A lot of Mastodon evangelists have been saying “it doesn’t matter which server you pick”. And that’s kind of true. I think those people just want to avoid having new users get stuck here, so they are trying to emphasize that being on a particular server doesn’t limit you to following people just on that server.

But on the other hand… of course it matters! I just went through the whole rigmarole of explaining how each server might have its own policies, features, list of blocked servers, or even a completely different version of the software. I'm not going to turn around after all that and say it doesn't matter. Some servers try to build little communities around a friend group or a common interest, while other servers deliberately don’t think of themselves as communities, they just want to be thought of as gateways to the larger fediverse. And also, this is a little complicated so I don’t want to get too deep in the weeds on it, but if you want to search for posts based on hashtags, you’ll might find that if you're using a smaller server, you won't find that many results from that many different servers. [3]

So your choise of server can indeed have a big impact on your experience. But if you’re new to all this, you have no way of knowing which features or policies will most impact your experience with Mastodon, which makes it hard to pick the perfect server for you.

In my opinion: that’s fine. You don’t have to pick the right server the first time, because as I mentioned before, you can easily move to a different server later, and keep all the followers from your account on your previous server.

Okay, I get it now. So just tell me the best way to sign up!

Since you can always move later, in my opinion the best approach for a newcomer is not to overthink picking a server. Pick any well-established server that seems like it's stable and widely trusted.

Here are some recommendations:

These reccomendations were updated on 11/22/2022 and any notes about registration status are current as of that day. But things change!

I do, of course, recommend that you review the about page of any instance you are considering joining, and make sure you are comfortable with the code of conduct, privacy policy, and other provided information before signing up.

Please note that some of these servers might currently be closed to new registrants, in order to make sure they do not grow to big too fast. However, if you're interested in a server that is closed, they may allow current members to invite new users, so you should check to see if you have any friends who are currently using those servers. See my section on "How can I find my old Twitter friends on Mastodon?", below.

  • joinmastodon.org has a list of servers which are currently accepting signups. Many of these are dedicated to particular interests or topics, and all of them have committed to meet the standards of the Mastodon Server Covenanant (which I'll explain momentarily).
  • As a subset of those, here are some medium-to-large size servers with no particular topic focus, that might be a good place to open your account. As of 11/22/2022, all four of the below servers are open to new users.
  • Here are some additional topic-based servers which you should take a look at. Many of these are currently closed to new registrations, but see the note above regarding invitations.
  • If you have a friend who uses Mastodon and they have a particular server they recommend, you can probably also just go with whatever they recommend. Trust your friends!

Bear in mind that, as of this writing, a lot of popular mastodon servers are getting slammed with traffic, due to a recent spike in attention and interest. So you’ll probably see some slowness or reliability issues at the moment.

Once you've got an account with the server you've picked, you can start posting, following, and deciding whether Mastodon is something you want to invest more of your time and attention in.

Once you know the ropes a bit more, you might find that you have some opinions about why a different server might be better for you, and move there. Or if you’ve got the technical knowledge, you might want to start your own server, like I did.

If anyone can start up a server, how do I know I can trust my server admins?

There isn't really a single good answer to this question, for Mastodon or for any other service. No matter what service you're signing up for, it’s a good idea to have a think about whether and why you trust them. Do I believe that the person or organization running this service has good intentions and won’t intentionally abuse my trust? Can I rely on them to be a competent steward of my data, and not accidentally leak all my info? Do I worry that they might just suddenly decide not to run the service anymore, and delete all my data without warning?

Your answers to these questions may vary from mine, which is only natural.

Maybe you will feel that the safest option is to run a server yourself, or join a server run by someone you already know well and trust.

Alternatively, you might reason that larger instances with long track records are the best bet.

Or, you could decide that mastodon.social and mastodon.online are the most trustworthy, because they are run by Eugen and associated with Mastodon gGmbH, a nonprofit organization that could theoretically be held accountable for misbehavior.

Or, you could drive Mastodon like a stolen car. Sign up with a burner email, and decide that it's no skin off your nose if it gets deleted or if your data gets leaked.

It might be helpful to know that all of the instances listed on joinmastodon.org have signed on to the Mastodon Server Covenant, which means they’ve made some commitments to uphold certain standards of moderation and availability. Obviously you need to decide for yourselves whether you trust a server to meet those commitments.

You might also want to know that Direct Messages are not encrypted on Mastodon[4], so your server admin could theoretically read them. As far as I know there's not actually an interface in the software for reading DMs, it's just that everything is stored on a server, and the person with access to that server could poke around in its contents. This is also true on Twitter, by the way, but unlike Twitter, Mastodon has a message in the DM interface that makes it clear your DMs are not encrypted.

I can’t answer the “who can I trust” question for you, nobody can. But I hope I’ve given you some info that frames it helpfully.

I tried to sign up and I’m getting unhelpful error messages. Seriously? If it’s this unreliable why should I bother?

Yeah obviously this sucks, and if the current issues with reliability are where you draw the line then I get that.

But I think this is just one of the rough edges that’s inherent to a platform which is growing rapidly. Twitter, in its early days, was known for its "Fail Whale."

It’s also much, much worse right now than usual, because most servers had to deal with huge spikes in traffic over the past few weeks and they’re struggling to quickly scale up their capacity. I think things will get more reliable as the sudden spike in interest tapers off, and server admins adjust to the new traffic.

In the mean time you might want to try a different server. If you’ve got your heart set on a particular server you’d like to join, but you’re not currently able, keep in mind that it’s relatively easy to migrate your account later, so there’s no harm in setting up shop somewhere else for the short term.

Okay, I’ve picked a server and signed up. Why are there three different timelines? What do Home, Local, and Federated mean?

Your Home timeline is a lot like the Twitter timeline (but chronological, not algorithmic). It shows you posts from everyone you follow (on your server or elsewhere), and anything they’ve “Boosted” (which is similar to retweeting or reblogging).

Your Local timeline shows public posts from everyone on your server, regardless of whether you’re following them. This is probably more useful if you’re on a small-to-medium sized server. In fact, having an interesting/useful Local timeline is one of the reasons people like to join smaller servers with friends, or servers based on geographic location or topics of interest.

Your Federated timeline shows all the posts your server knows about. This means it includes all the posts from the Local timeline, plus all the public posts from accounts that people on your server are following. This means that if you're on a smaller server like mine, where there are only five or six users, following less than a hundred people each, the total universe of people in the federated timeline is kind of small. But if you're on a larger server, where tens of thousands of people are following hundreds of thousands of accounts, the federated timeline will be more lively. And since the federated timeline is the basis for search results, hashtag searches are more fruitful. This is one of the benefits of being on a huge server.

[editied 11/13/2022 to add:] You mentioned I could move servers. How does that work?

Based on early feedback to this post it sounds like a lot of people are curious about moving servers. So I'm happy to add more information about that.

If you want step by step instructions, this guide from FediTips is really helpful. I wish I'd known about it when I moved servers, because there are a couple extra steps they recommend which would have saved me some work.

But here's the basic gist:

  1. First, you start by creating your new account on your new server.
  2. Then, you log into the preferences on your new account and let it know you'd like to move from your old account.
  3. Then, you log into the preferences on your old account and let it know you'd like to move to your new account.
  4. You might need to wait a little while for stuff to happen on the back end.
  5. Once this is done, all your followers will be following the new account instead of the old account.
  6. However, the list of people you are following won't have come over. You'll have to import your old list of follows. The FediTips link above explains how to do this.

After this process is done, your old account will still exist, but it will have a note indicating where you've moved to. It's best to leave that account in place with that note, so that if someone follows a link to your profile they will be able to find you. But if you would prefer to delete your account, you can do that as well.

In my opinion, the biggest flaw in this process is that your posts do not move from one account to the other. So even though your new account will have all your followers, all your follows, and some of your preferences, it won't have any posts on it. All your old posts will stay where they were. I am sure some people will see this as a huge problem, while others won't mind. It's possible that this will change in the future, but for now that's how it is.

[editied 11/22/2022 to add:] How can I find my old Twitter friends on Mastodon?

Mastodon doesn't have any built in features to find users who you may know from other apps, but there are some third party services that can scrape your Twitter data (with your permission) to find users who may also be on Mastodon.

I recommend Fedifinder or Debirdify. Both of these services work by searching the profiles of people you are conneced to on Twitter to see if they contain anything that looks like it might be a link to a Mastodon account or other fediverse presence.

Of course, this also means that if you put your Mastodon account in your Twitter bio or display name, it will help other people find you the same way. The best format for doing this is @username@server.name.

Any other tips?

My main point of this post is not to give you a full user's guide, it's to demystify the broader concepts of Mastodon and point you in the right direction to get you started.

But oh, fine, here are some basic tips for using Mastodon once you're up and running.

  • Make sure you read your server’s code of conduct, and agree to abide by it. Most servers have put a fair bit of thought into their CoC and take it seriously, so you should respect that.
  • Instead of tweets, they're called toots, or just posts if you think that's too silly of a word. Instead of retweeting, we have boosting.
  • There's no functionality analogous to "Quote Tweets", and I think there's a good chance there never will be. Lots of people prefer it that way.
  • Maybe don't usethe official app. Mastodon has an official mobile app, but it’s actually pretty new and a lot of people think it's not a great app. There are other apps which have been around longer and are better liked. I think the current consensus is that Metatext is the best app for iPhones, and Tusky for Android, but if you ask around on Mastodon I am sure folks will have other opinons.
  • People on the fediverse really like you to use Content Warnings when you are posting content that other people might not want to see without opting in.[5] This includes some obvious things like violence or nsfw content, but many people also prefer that you use content warnings for a broad range of kinds of content, including discussions of mental or physical health, media spoilers, discussion about politics or elections, or even just discussion topics that might be mildly annoying. Please bear in mind any guidelines that your server provides with regard to the use of content warnings. I think most people will be fine if you slip up sometimes, but folks do really appreciate when you put the effort in to learn the discussion courtesies that are customary in your community.
  • Likewise, people on the fediverse would really prefer that you add descriptive alt text whenever you post an image. Everyone forgets from time to time, but you should make it a habit to never post an image without descriptive alt text.
  • It’s a good idea to post an introduction post with the #Introduction hashtag, letting folks know who you are and what you’re all about. If you search that hashtag on your server you will probably see other people’s introductions, which will give you some idea of what kind of things people tend to put in their introductions (and hopefully, also give you an opportunity to find cool people to follow).

There’s a lot more I could say about how to get the most out of Mastodon, but I’ve got to draw the line somewhere.

But that’s not enough tips, I want even more tips! Tip me!

No! I'm done! I've tipped enough!

For more tips I recommend following @mstdn.social@FediTips, and browsing the FediTips website. Another great resource is An Increasingly Less-Brief Guide to Mastodon by @elekk.xyz@noelle. And if you're curious to know more about the philosophy and practicalities behind running an intentionally small Mastodon server, like I do, Run Your Own Social by Hometown creator Darius Kazemi is a great read.

If you have more questions, then I am eager to help. If you have feedback on this post, I'd love to hear how I can make it more helpful. You can reach out to me on mastodon at @tom@labyrinth.social, or if you aren’t even on Mastodon, you can also email me at tom [at] nowwearealltom [dot] com.


  1. I'd be remiss if I didn't mention that Mastodon is only one part of the fediverse. Mastodon servers talk to each other in a language called ActivityPub, and there are actually lots of other services that use ActivityPub, which means your Mastodon account can follow accounts that aren't even using Mastodon, but entirely different ActivityPub services, like Pleroma, Friendica, Bookwyrm, Pixelfed, and even some WordPress blogs, as well as many others. But for the purposes of this post I'm going to keep it simple and just talk about Mastodon. ↩︎

  2. Actually, my own personal private server, labyrinth.social, doesn’t use Eugen’s official version of Mastodon, it uses Hometown, a fork created and maintained by Darius Kazemi. ↩︎

  3. Okay, fine, twist my arm, I'll go a little into the weeds on hashtags. As I explain in another section of this post, your server has a "federated timeline", which is a timeline of the whole universe of posts it knows about. When you search for a hashtag, it's pulling those results from all the posts in your server's federated timeline, so if you have a very active, lively federated timeline, you'll get more results. ↩︎

  4. Eugen has mentioned that encrypted DMs are under consideration for a future Mastodon update, but I don't know if it's being actively worked on. I am doubtful that Twitter would ever implement end-to-end encryption for DMs, but hey, Elon could prove me wrong! EDIT 11/19/2022: Actually, turns out he might! Hats off to Elon, if Twitter ends up having this in place before Mastodon does. ↩︎

  5. Actually there's a fair bit of debate going on right this very moment on Mastodon about content warnings, when to use them, and whether it's fair or appropriate for you to expect (or demand) other people to use them. There's some culture clash between people who have been on Mastodon a while and people who are just joining now, and not everything has shaken out. Maybe it never will, or maybe the norms will change going forward, but these are my tips, so for now I am going to advse you to err on the side of overusing Content Warnings. ↩︎